Study On Active Control Techniques Of Ultra-stable Vehicular Platform

In order to satisfy the higher vibration isolation requirements of giantvehicularphoto-electric tracking equipment, the vehicle platform must achieve high vibrationisolation requirements within the range of full frequencies. Passive vibration isolationcannot meet the requirements of the vibration isolation. The vehicle platform should bedesigned with vibration isolation structure combined passive control and active control.As the main purpose of the study on active control techniques of ultra-stable vehicularplatform, this thesis carries out the following work:First of all, this thesis designs ultra-stable platform isolation scheme using the airspring as passive vibration isolation components andthe voice coil motor as activevibration isolation components, selects the air spring, voice coil motor and sensor, anddesigns the structure of the ultra-stable platform. Four degrees of freedom dynamicsanalysis model and dynamics equation are established. The natural frequencies ofvibration isolation system are calculated, the vibration transmissibility of passivevibration isolation system and active vibration isolation system under the floordisturbance is studied.Secondly, this thesis establishesthe state space equation of ultra-stable vehicularplatform in the sensor coordinate system,designs the LQR controller of the vibrationisolation system. By establishing the simulation model, the vibration transmissibility ofactive control and passive control is studied stimulated by single frequency harmonicsignal,random excitation signal and complex excitation signals. According to thesimulation results, under active control the vibration isolation effect of the ultra-stableplatform is well; the requirement of the micron level vibration isolation is satisfied.Finally, through the selection of the driver and controller and wiring the hardwareof the control system, this thesis realizes the hardware development of the active controlsystem. Through the comparative study of software integral andfiltering algorithm, thisthesis gets an integral and filtering algorithm which has low error rate combinedtrapezoidal integral algorithm, Simpson integral algorithm and high-pass filteringalgorithm. In Automation Studio programming environment, the software programs arewritten, the software development of active control system is realized.